Fan blades or impellers



March 15, 1955 ox 2,704,130

FAN BLADES OR IMPELLERS Filed Jan. 2, 1955 INVENTOR Ge 0 lye R. C02:

ATTORNEY United States Patent FAN BLADES 0R IMPELLERS George R. Cox, Belton, S. C.

Application January 2, 1953, Serial No. 329,309

Claims. (Cl. 170172) My invention relates to impeller or blade structure for fans or the like.

A primary object of the invention is to provide a fan blade structure capable of creating or propelling streams of air or the like in opposite directions simultaneously, as the fan blade structure turns in one direction upon its axis of rotation.

A further object is to provide a fan impeller including a blade or blades pitched so as to create a first air stream in one axial direction, the blade or blades having opening means to receive air during the rotation of the impeller and discharging the air to form a second air stream in a direction axially opposite to the first air stream.

A further object is to provide a fan blade structure of the above-mentioned character which is compact, simplified, sturdy and durable and efficient in operation.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings, forming .a part of this application, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a perspective view of an impeller or blade structure embodying the present invention.

Figure 2 is a side elevation of the same.

Figure 3 is a further side elevation of the impeller edgewise with respect to the hub portion thereof.

Figure 4 is a central vertical longitudinal section on line 44 of Figure 2.

Figure 5 is a horizontal transverse section on line 55 of Figure 2, and drawn on an enlarged scale.

Figure 6 is a similar section taken on line 66 Figure 2, and,

Figure 7 is a side elevation of an impeller or blade structure having four blades and embodying a modifica tion of the invention.

In the drawings, where for the purpose of illustration are shown preferred embodiments of the invention, attention is directed first to Figures 1 to 6 inclusive, wherein an impeller or blade structure is illustrated having a pair of diametrically oppositely disposed blades 10 and 11, preferably formed integral with a central hub portion 12. The blades 10 and 11 are twisted or pitched in a direction to propel air or the like axially as the impeller rotates upon its axis in one direction.

The hub portion 12 which may be generally circular as viewed axially, Figure 2, is hollow, and comprises axially opposed spaced sides 13 and 14, integrally joined about their margins by the circularly curved marginal wall 15. The side wall 13 of the hub portion 12 is closed or imperforate, and may have rigidly secured thereto by any suitable means a raised boss or disc 16, in turn rigidly secured to or formed integral with an axial shaft 17, which may be the armature shaft of an electric motor or the like. The opposite side wall 14 of the hollow hub portion 12 has a large circular air discharge opening 18 formed centrally therein, as shown.

The two blades 10 and 11 are pitched so as to create or propel a stream of air or the like axially of the impeller and toward the side of the hub portion 12 beyond which the shaft 17 extends, when the impeller is turning in the direction of the arrows, Figures 2 and 5.

The blades 10 and 11 are provided in their leading edges with elongated openings or slots 19, preferably extending along the major portions of the lengths of the 2,704,130 Patented Mar. 15, 1955 blades, as shown. The slots 19 lead into internal longitudinal passages 20, formed within the blades 10 and 11, in turn leading radially inwardly and communicating with the interior of the hollow hub portion 12, at diametrically opposite points, Figure 2. The internal passages 20 preferably have inclined or longitudinally curved inner walls 21, so that the passages will tend to scoop the air and direct it radially inwardly towards the hub of the impeller as the impeller rotates clockwise, Figure 2. The slots 19 and internal passages 20 of the blades 10 and 11 form upon the blades spaced opposed side walls 22 and 23, and the leading edges 24 of the blade side walls 23 are preferably cut back or spaced laterally inwardly somewhat of the leading edges of the blade side walls 22. The blades 10 and 11 have their longitudinal edges gradually curved in a conventional manner, and the cutback edges 24 are likewise curved longitudinally and follow the curvature of the adjacent edge of the blade. The outer tips of the blades 10 and 11 are preferably rounded as at 25, and the blades may be solid between the tips 25 and the inner walls 21 of the passages 20. It should be thoroughly understood that the slots 19 are formed in the leading edges of the blades 10 and 11, as the blade rotates clockwise or in the direction of the arrow, Figure 2, and that the pitch of the blades 10 and 11 is such as to propel a stream of air axially beyond the imperforate hub side 13 or along the shaft 17, as the blade turns clockwise in Figure 1.

As this clockwise rotation of the impeller takes place and an air stream is thus formed in one axial direction, air is simultaneously forced into the slots 19 due to the clockwise rotation of the impeller, and this air is thence forced radially inwardly through the passages 20 and to the interior of the hollow hub portion 12, from which it is expelled in an axial stream through the discharge opening 18. This axial stream of air from the opening 18 is flowing in the opposite axial direction from the air stream caused by the pitch of the blades 10 and 11, and it is thus seen that my impeller or blade structure is capable of blowing or propelling air or the like in opposite axial directions, simultaneously, while rotating in one direction about its axis of rotation.

In Figure 7 I have shown a modification of the invention wherein the impeller or blade structure comprises four circumferentially equidistantly spaced blades 26, 27, 28 and 29, all integ r ally secured at their inner ends to a central hollow hub portion 30, identical in construction with the hub portion 12. One side of the hub portion 30 has rigidly secured to it the shaft 17, and the opposite side of the hub portion 30 is provided with the discharge opening 18, described in connection with the first form of the invention. The four blades 26, 27, 28 and 29 are provided in their leading edges With the same openings or slots 19, provided in the blades 10 and 11, and the blades 26 to 29 also have the same internal passages 20 leading radially into the interior of the hollow hub portion 30. Except for their number, the blades 26 to 29 are identical with the blades 10 and 11, and are pitched in a corresponding manner to create one axial air stream, in one direction, as the four bladed impeller rotates clockwise in Figure 7. That air stream is in the direction opposite to the other air stream which is caused by the discharge of air axially through the opening 18, in the identical manner described in connection with the first form of the invention. Obviously, the impeller may comprise any desired number of blades, and I do not wish to restrict the invention to any particular number of blades.

It is to be understood that the forms of the invention herewith shown and described are to be taken as preferred embodiments of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjected claims.

Having thus described my invention, I claim:

1. A unitary rotary impeller for air circulating fans capable of creating air streams in opposite directions longitudinally of its axis of rotation simultaneously, comprising a hollow hub portion adapted for connection with a rotary drive shaft and provided in one side only with a relatively large air discharge opening in substantial alignment with the axis of rotation of the impeller, and a pair of impeller blades secured to said hub portion and extending radially thereof and pitched to create a first air stream in one direction longitudinally of the axis of rotation of the impeller, said blades being provided in their leading edges with long slots extending longitudinally of the blades throughout a major portion of their lengths, said blades including hollow portions communicating with said slots and the hollow hub portion and adapted to receive air entering through said slots and convey such air into the hollow hub portion where the air is discharged through said air discharge opening for creating a second air stream longitudinally of the axis of rotation of the impeller in a direction opposite to the first air stream.

2. A unitary rotary impeller for air circulating fans and capable of creating air streams in opposite directions simultaneously, comprising a hollow portion adapted for connection with a rotary drive shaft and provided in one side with an air discharge opening arranged sub stantially axially of the impeller, and a pair of generally radial hollow impeller blades secured to the hub portion and having their interiors in direct communication with the interior of the hollow hub portion and pitched to create a first air stream in one direction axially of the impeller, said blades being provided in their leading edges with openings through which air enters the hollow blades during rotation of the impeller, such air passing into the hollow hub portion and discharging through said discharge opening of the hollow hub portion for creating a second air stream axially of the impeller in a direction opposite to the first air stream.

3. A unitary rotary impeller for air circulating fans and capable of creating air streams in opposite directions simultaneously, comprising a hollow hub portion having a closed side for connection with a rotary drive shaft and an open side for discharging air in one direction axially of the impeller, and a plurality of impeller blades secured to the hollow hub portion for rotation therewith and pitched to move air axially of the impeller in the opposite direction to the air passing from the open side of the hollow hub portion, said blades having openings in their leading edges to receive air during rotation of the impeller and internal passages leading from said openings into the interior of the hollow hub portion, said passages including passage side walls which are inclined with respect to the longitudinal axes of said blades for directing the air radially inwardly toward the hollow hub portion.

4. A unitary rotary impeller for air circulating fans capable of creating air streams in opposite directions axially of the impeller simultaneously, comprising a multibladed hollow impeller body portion adapted for connection with a rotary driving element and having an air discharge opening arranged axially of the impeller body portion through which air may be discharged in one axial direction, the blades of the multi-bladed impeller body portion being pitched to drive air axially of the impeller body portion in the opposite direction to the air passing from said air discharge opening, said blades being provided in their leading edges with air intake openings through which air may enter the interior of the multibladed hollow impeller body portion during rotation of the same in one direction.

5. A unitary rotary impeller for air circulating fans and capable of creating air streams in opposite directions simultaneously comprising an impeller body portion adapted for connection with a rotary driving element and including an impeller blade pitched to create a first air stream in one direction axially of the impeller body portion during rotation of the same, said blade having an opening in its leading edge to receive air during rotation of the impeller body portion, the impeller body portion having an internal passage communicating with said opening of the blade, said impeller body portion having an unobstructed air discharge opening substantially axially of the impeller body portion through which air from the internal passage is discharged during rotation of the impeller body portion to create a second air stream axially of the impeller body portion in a direction opposite to the first air stream.

References Cited in the file of this patent UNITED STATES PATENTS 1,349,482 Wood Aug. 10, 1920 1,399,157 Rystedt Dec. 6, 1921 1,540,108 Degen June 2, 1925 1,972,335 Gardner Sept. 4, 1934 2,246,706 Vorhies June 24, 1941 2,283,068 Johnson May 12, 1942 2,476,002 Stalker July 12, 1949 2,491,025 Beckert Dec. 13, 1949 2,508,673 Guthier May 23, 1950 

